This invention relates to an operator for opening and closing a closure such as a window and, more particularly, to an operator for moving the window sash between open and closed positions such as by swinging the sash of an awning window. Customarily, such operators include a driven member operatively connected to the sash and a rotary drive member connected to the driven member. A crank arm projects radially outwardly from the drive member and is used to manually turn the drive member so as to move the sash.